Manufacture of compound tubes.



No. 831,887. PATENTED SEPT. 25, 1906.

J. H. NICHOLSON. MANUFACTURB 0F COMPOUND TUBES.

APPLICATION FILED MAY 18. 1905.

i i I wrmessss mwen-ron WYNMMW UNITED STATES PATENT OFFTO.,

JOHN H. NICHOLSON, OE PITTSBURGHPENNSYLVANIA, ASSIGNOR TO NATIONAL TUBE, COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF NEW JERSEY.

NIANUFACTURE OF COMPOUND TUBES.

Patented Sept. 25, 1906.`

To all whom it may concern:

Be it known that I, JOHN H. NICHOLSON, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new` and useful Improvement in the Manufacture of Com ound Tubes, of which the following is a full, c ear, and exact description, reference being had to the' accom anying drawings, forming part of this speci cation, in which- Figures l and'2 are diagrammatic views illustrating the different steps of my irnproved method of manufacture.

My present invention is an improvement in the manufacture of com ound tubes which is described, and 'claimedp in an a plication filed by me on April 25, 1904, erial No. 204,704. In that application I describe the manufacture of a steel or iron tube provided with a welded covering of nickel, applied either to the exterior or interior surface, or to both, in order to give the tube a non-corrodible surface, and I claim, among other things, as a new article of manufacture a tube havin a steel bod with a thin nickel tube welde thereto an also the method of making a compound tubular blank, consisting in nesting together a heavy-walled hollow steel blank and a thin-walled nickel tube, heating the com ound blank to a welding temperature, an then compressing, welding, and rolling the same into a tube, substantially as described in said application. In practicing this method I have found that if nickel linings lighter than fifteen per cent. are produced some difficulties are encountered, owing to changes occurring in the roportional thicknesses existing between t e nickel and steel that tend to roduce thin places or spots in the nickel lining. This is due to the irregularities of the interior surface of the pierced steel billet and to the very thin nickel tube that is Welded thereto, and there is danger that in the finished tube there might be some spots or places not thoroughly covered with nickel. The ordinary pierced billet that is best suited for swagin -mill work is from fiveeighths to three-fourt s of an inch thick. If a ten-per-cent. lining is required, the liningtube will have to be fifteen to sixteen gage, and if a five-per-cent. lining is required the lining-tube will have to be twenty to twentyone gage.

- complished by Difficulties arise in maintaining the original pro ortional thicknesses existing between the nic el and steel when welding a very thin nickel tube to the rough interior surface of the steel billet. ties and to secure a method whereby a very thin nickel lining can be secured without materially disturbing the proportional thicknesses existing between the nickel and steel, I resorted to improvements in the former method of manufacture and invented animproved method which contains novel features and eliminates the diiculties originally' encountered. I observedin operating under the original method that the thicker the liningtube the easier it was to effect a satisfactory weld and less disturbances occurred between the roportional thicknesses of the nickel and stee in the welding and rolling operation, and this suggested the following improvement over my ormer method: I make a lined tube, using the method described in the abovementioned application, with a nickel lining somewhat heavier than would be required to protect it from corrosion. I then take this compound tube, which has a substantial wall sufiiciently heavy for securing a satisfactory weld, and in a secondary operation Weld this compound tube into a pierced blank. This secondary operation of welding may be actelescoping the compound tube within the heavy-walled hollow steel blank, heating it to a welding-heat and rolling it over a mandrel, so as to reduce its thickness and elongate it, thus welding the primary compound tube firmly to the hollow steel blank. On account of the thicker lining used the nickel retains its relative thickness asV compared with the steel and can be rolled and drawn into boiler-tubes with a nickel lining as light as two and one-half per cent., saidlining being distributed evenly over the interior surface of the tube, thoroughly protecting the interior surface from oxidation and corrosion.

The following statement will afford working directions of the best nature now known to me of applying the principles of this new method for the making of v a six-per-cent. nickel-lined tube; but those skilled in the art can modify it in many ways so as to produce tubes of dierent thicknesses of lining, so as To overcome these diflicul- IOO " billets having walls, say, nine-sixteenths of thickness.

an inch thick, the welding-surfaces of both the' steel' blank andthe nickel tube havingbeen cleaned from scale. I then heat 'such composite blanks after having expanded the ends of. the nickel tube or otherwise taken precaution to prevent oxidizing of the meeting surfaces o the nickel and steel and roll the same out into a-com ound tube of, say, three-sixteenths-inch Wall). This step of the o eration is illustrated in Fig. 1, in which t e numeral 2 designates the pierced billet` and 3 the nickellining. 4 is the mandre over which the rolling operation is done, and 5 designates rolls vof? any suitable character. In 'the original composite blank the thickness ofthe steel was nine-sixteenths of an inch` andthe nickel three-sixteenths of an inch, or twenty-five per cent. This same relative thickness of nickel and steel exists in the rolled tube, or nine sixty-fourths ofthe thickness -is steel and three sixty-fourths, or twenty-five per cent., is nickel. I then take this compound tube and cut it into pieces of the desired len th and telescope these pieces into pierced bi letsl of steel, with walls, say, five-eighths of an inch thick. This operation is illustrated in Fig. 2, yin which the originally-formed tube, com osed of the steel-portion 2 and the nicke 'lining-3, are shown as inserted in a pierced steel 'blank 6. 7,- is the mandrel, and 8 designates any suitable rolls. This double composite blank or `billet has a steel Wall ive-eighths of an -inch thick or forty sixty-fourths plus nine sixty-fourths, or forty-nine siXty-fourths,-and a nickel vlining of three sixty-fourths, or almost six per cent. of the total. I then take this double com osite blank, Weld and elongate it by means o rolling over a mandrel, and reduce it to a tube with Aa three-sixteenths-inch Wall, the nickel and steel retaining their same relative'thickness. This tube can then be cold-drawn vinto different sizes and gages, as required.'- This same method for securing a thin covering for the outside of 'tubes can be employed by first making a nickel-covered tube with the nickel covering relatively heavier than would berequired for non-corrosive purposes, then telesco ing this covered tube over a heavy- Walle pierced billet, Welding the same, and roll-ing'it down to the necessary The same proportions of steel and nickel can lbe used as are given in the makin of `the'six-per-cent. lined tube, if so desire This same method can be used for producing a tube with both a thin interior lining and a thin exterior covering' by first making a tube as' described above with a thin nickel lining and telescoping it into a similarly-made tube with a .thin nickel covering, and heating, welding, and rolling the same over a mandrel, as previouslydescribed.

Attention is called to the factthat in preparing'the original nickel tube for use as a ining-tube in the primary steel blank it is not necessary to cold-draw it.; also, that in using the lined tube made in the first welding operation as a lining-tube for use in the secondary operation ahot-rolled tube is used. The omitting of the cold-drawing o lerationin the preparation of the tubes use for linin purposes very materially decreases the mil costs of this new method, and the total manufacturing costs (exclusive of the value f the steel and nickel)are no more than in my o riginal method, and by its use we can eatly reduce the amount of nickel require as tubes with a lining as light as two and one-half per cent.' have been successfully made in the y manner described.

The method ofwelding and rollin used for making either'the linedor covere tube or a tube both lined and covered can .be

changed or modified from that described 1 without de arting from the spiritof this invention, W 4'ch pertains, rlmarily, to the means used in securing a tliin lining or covering of even thickness by telescopin in tol or over a' heavy-Walled steel or iron lanka tube that 'has already been lined or covered with nickel in such a manner as will prese):vey the proportional "thicknesses of steelfanfdnicke down to a tube of the desired sizes and thick-' ness with the object of securing a thinner and more even lining or covering thancan vbesef cured by primarily telescoping a .nickel lining or covering into or over a v'heav -walled hol-.- lowl billet, then welding and rolling the same down to a tube of the desired size and thickness of' wall. By this method `of manufacture `I overcome the difficulties, abovev` re- IOC and then welding and rollingsame- IIO ferred to, since the greater thickness of. they nickel lining employed in the first welding and reducing operation is suflicient to maintain a. prolper thickness of the' lining at all., points in t e finished tube. In the following claims I use the term f tu-,1

bular sheathing enerically as meaning a tube of nickel appI or exterior of the finished tube.

I elaim-l v 1. The method herein describedof making'` ied eitherto the interior a compound iron or steel tube with a thin tuand rolling this compound blank into fr tuhe for the urpose of securing a thin and even nickel s ieathing; substantially as described. j

2. The method herein described of making a. compound iron or steel tube with a thin nickel or nickel-alloy lining Welded thereto` welded theretol which consists in telesen` f over a heavy tubulin' iron or steel hln-nh en iroii or steel tube which hns :i nickel eoixerim;` welded thereto, :1nd teleseoping thereinlo :in ce iron or steel tube which has n nickel lining welded thereto, then heating, welding :ind rollin" this double Compound hhmh info tube or the purpose ol' securingr :i thin und even nickel covering and lining; sn listini? in liv' 11:1; as described. Y i

In testimony whereof I have heren` t w1 my hand May 15, 1905..

JOHN ll'. NlCllOli'li Witnesses THOMAS W. BAKEWELL, Il. M. CORWIN. 

